Chandrayaan -1 in lunar orbit

Monday, November 10, 2008, 6:19 by Tech Correspondent

Creating history, India’s first unmanned spacecraft mission to moon, the Chandrayaan-1, has entered lunar orbit. This is the first time that an Indian built spacecraft has broken away from the Earth’s gravitational field and reached the moon.

According to ISRO sources, the firing of Chandrayaan-1 spacecraft’s liquid engine for a duration of 817 seconds saw the highly complex lunar orbit insertion manoeuvre happen from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network at Bangalore. The space research organization said that the Indian deep space network (IDSN) at Byalalu had supported the crucial task of transmitting commands and continuously monitoring the event with two dish antennas, one measuring 18 m and the other 32 m. The ISRO has said that the spacecraft would take about 11 hours to go round the moon once in the orbit.

The ISRO said that Chandrayaan-1’s liquid engine was fired when the spacecraft passed at a distance of about 500 km from the moon to reduce its velocity to enable lunar gravity to capture it into an orbit around the moon. It has been observed that the spacecraft is currently orbiting the moon in an elliptical orbit that passes over the polar regions of the moon. It has been pointed out that the Terrain Mapping Camera, one of the 11 scientific instruments of the spacecraft, has been opened twice to take pictures of the earth and moon.

Explaining that the performance of all the systems onboard Chandrayaan-1 has so far been normal, the ISRO believes that in the coming days, the height of Chandrayaan-1 spacecraft’s orbit around the moon will be carefully reduced in steps to achieve a final polar orbit of about 100 km height from the moon’s surface. With this set to happen, the Moon Impact Probe (MIP) of the spacecraft will be released to hit the lunar surface. Later, the other scientific instruments will be turned on sequentially leading to the normal phase of the mission, it said.

The successful manoeuvre of Chandrayaan-1 into the Lunar orbit has made India become the fifth country to send a spacecraft to Moon. The United States, the erstwhile Soviet Union, Japan and China have done the feat before, apart from the European Space Agency (ESA), which is a consortium of 17 countries.